A man is going to an Antique Car auction. All purchases must be paid for in cash. He goes to the bank and draws out $25,000.
Since the man does not want to be seen carrying that much money, he places it in 15 envelopes numbered 1 through 15. Each envelope contains the least number of bills possible of any available US currency (for example, no two tens instead of a twenty).
At the auction he makes a successful bid of $8322 for a car. He hands the auctioneer envelopes 2, 8, and 14. After opening the envelopes the auctioneer finds exactly the right amount.
How many ones did the auctioneer find in the envelopes?
Since the man does not want to be seen carrying that much money, he places it in 15 envelopes numbered 1 through 15. Each envelope contains the least number of bills possible of any available US currency (for example, no two tens instead of a twenty).
At the auction he makes a successful bid of $8322 for a car. He hands the auctioneer envelopes 2, 8, and 14. After opening the envelopes the auctioneer finds exactly the right amount.
How many ones did the auctioneer find in the envelopes?
Answer:
One.
Unfortunately, Lucas Jones didn't provide a more elaborate explanation. But thanks to Ronald A. Laski we can now present a more acceptable explanation:
In Envelope #14, there are:
81 $100 bills = $8100
1 $ 50 bill = $ 50
2 $ 20 bills = $ 40
1 $ 2 bill = $ 2
----- +
$8192 (total amount of money for Envelope #14) In Envelope #8, there are: 1 $100 bill = $100
1 $ 20 bill = $ 20
1 $ 5 bill = $ 5
1 $ 2 bill = $ 2
1 $ 1 bill = $ 1 <- that's the one!
----
$128 (total amount of money for Envelope #8)
Envelope #2 has 1 $2 bill in it, which is its total amount also.
Now $8192 + $128 + $2 = $8322. And that is the winning bid!
The amount of money in each envelope is 2 ^ (# of envelope - 1), except for envelope 15, which contains $8617.
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